Save and slect an waypoint to navigate using the flysky i6 remote

Hello, I have a bait boat with pixhawk 2.4.8, and I need to select an waypoint to navigate using a switch on my flysky remote . It is possible to do this? I see a video on YouTube with somebody doing this.Autopilot Fb pilot v.Pro manual - YouTube
I use ch7 to save a wp, but after thet I don’t know how can I select an wp number to navigate to this directly from my remote switch .
I have the the same frimewere on my Flysky I6 like in the video .
Thank you in advance.